1. Field of Invention
The present invention relates to a method for removing pad nodules. More particularly, the present invention relates to a method for removing pad nodules utilizing deionized water and developer.
2. Description of Related Art
Pads which are made of aluminium or aluminium/copper alloy are formed on a wafer for bonding and testing. An etching process such as plasma etching is performed for forming the pads. If chloride plasma is utilized in the etching process, a corrosion effect is generated. To avoid the corrosion effect, fluorine plasma is utilized. However, fluorine easily remains on the pads after the plasma process and then pad nodules (as shown in FIG. 1) are formed on the pads because fluorine remains on the pads reacts with the pads to produce AlF.sub.3. The pad nodules affect the reliability of the subsequently formed devices.
A wet rinse process is usually performed after the plasma etching process to remove fluorine remains on the pads. But fluorine is difficult to be completely removed, although the wet rinse process is performed. Therefore, an oxygen plasma process may be performed to help removal of fluorine, but the oxygen plasma process also affects the reliability of the subsequently formed devices.